/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package io.netty.buffer;

import io.netty.util.Recycler;
import io.netty.util.internal.PlatformDependent;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.FileChannel;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.ScatteringByteChannel;

class PooledHeapByteBuf extends PooledByteBuf<byte[]> {

  private static final Recycler<PooledHeapByteBuf> RECYCLER = new Recycler<PooledHeapByteBuf>() {
    @Override
    protected PooledHeapByteBuf newObject(Handle<PooledHeapByteBuf> handle) {
      return new PooledHeapByteBuf(handle, 0);
    }
  };

  static PooledHeapByteBuf newInstance(int maxCapacity) {
    PooledHeapByteBuf buf = RECYCLER.get();
    buf.reuse(maxCapacity);
    return buf;
  }

  PooledHeapByteBuf(Recycler.Handle<? extends PooledHeapByteBuf> recyclerHandle, int maxCapacity) {
    super(recyclerHandle, maxCapacity);
  }

  @Override
  public final boolean isDirect() {
    return false;
  }

  @Override
  protected byte _getByte(int index) {
    return HeapByteBufUtil.getByte(memory, idx(index));
  }

  @Override
  protected short _getShort(int index) {
    return HeapByteBufUtil.getShort(memory, idx(index));
  }

  @Override
  protected short _getShortLE(int index) {
    return HeapByteBufUtil.getShortLE(memory, idx(index));
  }

  @Override
  protected int _getUnsignedMedium(int index) {
    return HeapByteBufUtil.getUnsignedMedium(memory, idx(index));
  }

  @Override
  protected int _getUnsignedMediumLE(int index) {
    return HeapByteBufUtil.getUnsignedMediumLE(memory, idx(index));
  }

  @Override
  protected int _getInt(int index) {
    return HeapByteBufUtil.getInt(memory, idx(index));
  }

  @Override
  protected int _getIntLE(int index) {
    return HeapByteBufUtil.getIntLE(memory, idx(index));
  }

  @Override
  protected long _getLong(int index) {
    return HeapByteBufUtil.getLong(memory, idx(index));
  }

  @Override
  protected long _getLongLE(int index) {
    return HeapByteBufUtil.getLongLE(memory, idx(index));
  }

  @Override
  public final ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
    checkDstIndex(index, length, dstIndex, dst.capacity());
    if (dst.hasMemoryAddress()) {
      PlatformDependent.copyMemory(memory, idx(index), dst.memoryAddress() + dstIndex, length);
    } else if (dst.hasArray()) {
      getBytes(index, dst.array(), dst.arrayOffset() + dstIndex, length);
    } else {
      dst.setBytes(dstIndex, memory, idx(index), length);
    }
    return this;
  }

  @Override
  public final ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
    checkDstIndex(index, length, dstIndex, dst.length);
    System.arraycopy(memory, idx(index), dst, dstIndex, length);
    return this;
  }

  @Override
  public final ByteBuf getBytes(int index, ByteBuffer dst) {
    checkIndex(index, dst.remaining());
    dst.put(memory, idx(index), dst.remaining());
    return this;
  }

  @Override
  public final ByteBuf getBytes(int index, OutputStream out, int length) throws IOException {
    checkIndex(index, length);
    out.write(memory, idx(index), length);
    return this;
  }

  @Override
  public final int getBytes(int index, GatheringByteChannel out, int length) throws IOException {
    return getBytes(index, out, length, false);
  }

  private int getBytes(int index, GatheringByteChannel out, int length, boolean internal)
      throws IOException {
    checkIndex(index, length);
    index = idx(index);
    ByteBuffer tmpBuf;
    if (internal) {
      tmpBuf = internalNioBuffer();
    } else {
      tmpBuf = ByteBuffer.wrap(memory);
    }
    return out.write((ByteBuffer) tmpBuf.clear().position(index).limit(index + length));
  }

  @Override
  public final int getBytes(int index, FileChannel out, long position, int length)
      throws IOException {
    return getBytes(index, out, position, length, false);
  }

  private int getBytes(int index, FileChannel out, long position, int length, boolean internal)
      throws IOException {
    checkIndex(index, length);
    index = idx(index);
    ByteBuffer tmpBuf = internal ? internalNioBuffer() : ByteBuffer.wrap(memory);
    return out.write((ByteBuffer) tmpBuf.clear().position(index).limit(index + length), position);
  }

  @Override
  public final int readBytes(GatheringByteChannel out, int length) throws IOException {
    checkReadableBytes(length);
    int readBytes = getBytes(readerIndex, out, length, true);
    readerIndex += readBytes;
    return readBytes;
  }

  @Override
  public final int readBytes(FileChannel out, long position, int length) throws IOException {
    checkReadableBytes(length);
    int readBytes = getBytes(readerIndex, out, position, length, true);
    readerIndex += readBytes;
    return readBytes;
  }

  @Override
  protected void _setByte(int index, int value) {
    HeapByteBufUtil.setByte(memory, idx(index), value);
  }

  @Override
  protected void _setShort(int index, int value) {
    HeapByteBufUtil.setShort(memory, idx(index), value);
  }

  @Override
  protected void _setShortLE(int index, int value) {
    HeapByteBufUtil.setShortLE(memory, idx(index), value);
  }

  @Override
  protected void _setMedium(int index, int value) {
    HeapByteBufUtil.setMedium(memory, idx(index), value);
  }

  @Override
  protected void _setMediumLE(int index, int value) {
    HeapByteBufUtil.setMediumLE(memory, idx(index), value);
  }

  @Override
  protected void _setInt(int index, int value) {
    HeapByteBufUtil.setInt(memory, idx(index), value);
  }

  @Override
  protected void _setIntLE(int index, int value) {
    HeapByteBufUtil.setIntLE(memory, idx(index), value);
  }

  @Override
  protected void _setLong(int index, long value) {
    HeapByteBufUtil.setLong(memory, idx(index), value);
  }

  @Override
  protected void _setLongLE(int index, long value) {
    HeapByteBufUtil.setLongLE(memory, idx(index), value);
  }

  @Override
  public final ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
    checkSrcIndex(index, length, srcIndex, src.capacity());
    if (src.hasMemoryAddress()) {
      PlatformDependent.copyMemory(src.memoryAddress() + srcIndex, memory, idx(index), length);
    } else if (src.hasArray()) {
      setBytes(index, src.array(), src.arrayOffset() + srcIndex, length);
    } else {
      src.getBytes(srcIndex, memory, idx(index), length);
    }
    return this;
  }

  @Override
  public final ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
    checkSrcIndex(index, length, srcIndex, src.length);
    System.arraycopy(src, srcIndex, memory, idx(index), length);
    return this;
  }

  @Override
  public final ByteBuf setBytes(int index, ByteBuffer src) {
    int length = src.remaining();
    checkIndex(index, length);
    src.get(memory, idx(index), length);
    return this;
  }

  @Override
  public final int setBytes(int index, InputStream in, int length) throws IOException {
    checkIndex(index, length);
    return in.read(memory, idx(index), length);
  }

  @Override
  public final int setBytes(int index, ScatteringByteChannel in, int length) throws IOException {
    checkIndex(index, length);
    index = idx(index);
    try {
      return in
          .read((ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length));
    } catch (ClosedChannelException ignored) {
      return -1;
    }
  }

  @Override
  public final int setBytes(int index, FileChannel in, long position, int length)
      throws IOException {
    checkIndex(index, length);
    index = idx(index);
    try {
      return in.read((ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length),
          position);
    } catch (ClosedChannelException ignored) {
      return -1;
    }
  }

  @Override
  public final ByteBuf copy(int index, int length) {
    checkIndex(index, length);
    ByteBuf copy = alloc().heapBuffer(length, maxCapacity());
    copy.writeBytes(memory, idx(index), length);
    return copy;
  }

  @Override
  public final int nioBufferCount() {
    return 1;
  }

  @Override
  public final ByteBuffer[] nioBuffers(int index, int length) {
    return new ByteBuffer[]{nioBuffer(index, length)};
  }

  @Override
  public final ByteBuffer nioBuffer(int index, int length) {
    checkIndex(index, length);
    index = idx(index);
    ByteBuffer buf = ByteBuffer.wrap(memory, index, length);
    return buf.slice();
  }

  @Override
  public final ByteBuffer internalNioBuffer(int index, int length) {
    checkIndex(index, length);
    index = idx(index);
    return (ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length);
  }

  @Override
  public final boolean hasArray() {
    return true;
  }

  @Override
  public final byte[] array() {
    ensureAccessible();
    return memory;
  }

  @Override
  public final int arrayOffset() {
    return offset;
  }

  @Override
  public final boolean hasMemoryAddress() {
    return false;
  }

  @Override
  public final long memoryAddress() {
    throw new UnsupportedOperationException();
  }

  @Override
  protected final ByteBuffer newInternalNioBuffer(byte[] memory) {
    return ByteBuffer.wrap(memory);
  }
}
